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FGUS73 KFGF 261213
ESFFGF
NDC005-027-071-301200-
PROBABILISTIC HYDROLOGIC OUTLOOK
NATIONAL WEATHER SERVICE EASTERN NORTH DAKOTA/GRAND FORKS ND
0657 AM CDT Fri Jun 26 2015
...DEVILS LAKE OUTLOOK FOR FLOOD POTENTIAL...
Devils and Stump Lakes
Long-Range Probabilistic Outlook
The National Weather Service is providing long-range probabilistic
hydrologic outlooks for Devils and Stump lakes between January
and September. They will not be provided between October and
December.
The AHPS graphics associated with this outlook will be on the web
no later than 10:30 AM this Friday under the experimental
long-range flood risk tab at...
water.weather.gov/ahps2/index.php?wfo=fgf
Depending on the season, the high or low water probabilities may
be omitted due to their applicability to the hydrologic situation.
Refer to the scheduling section farther on in this message.
. Chances of Devils and Stump Lakes rising above given lake levels...
The probability of exceeding a given lake level is the percentage
of maximum lake level rises that are above that level for all the
years that were run through the model using the precipitation
and temperatures for those years during the valid period of the
outlook.
Interpretation Aid...There is a 50 percent chance that Devils
Lake will rise above 1451.7 feet during the valid period and
only a 5 percent chance that it will rise above 1451.9 feet.
Probabilities for exceeding listed lake levels
FROM JUNE 22, 2015 TO SEPTEMBER 30, 2015
LOCATION 95% 90% 75% 50% 25% 10% 05%
-------- ------ ------ ------ ------ ------ ------ ------
DEVILS LAKE.....
CREEL BAY 1451.7 1451.7 1451.7 1451.7 1451.7 1451.8 1451.9
STUMP LAKE.....
EAST STUMP LAKE 1451.7 1451.7 1451.7 1451.7 1451.7 1451.8 1451.9
. Previous record high lake levels...
* The most recent USGS provisional record daily average height
for Devils Lake at the Creel Bay gage:
...1454.30 feet on June 27 of 2011
* Previous records:
...1452.05 feet on June 27 of 2010
...1450.93 feet on June 27 of 2009
...1449.20 feet on May 9 of 2006
...1449.18 feet on June 17 of 2004
...1449.17 feet on August 2 of 2005
* For more high water marks...see the USGS flood tracking charts at:
HTTP://ND.WATER.USGS.GOV/FLOODTRACKING
. Chances of Devils and Stump Lakes falling below given lake
levels...
The probability of not exceeding a given lake level is the
percentage of lake level falls that are below that level for
all the years that were run through the model using the
precipitation and temperatures for those years during the
valid period of the outlook.
Interpretation Aid...There is a 50 percent chance that Devils
Lake will fall below 1450.0 feet during the valid period and
only a 5 percent chance that it will fall below 1449.6 feet.
Probabilities for non-exceeding listed lake levels
FROM SEPTEMBER 1, 2015 TO NOVEMBER 30, 2015
LOCATION 95% 90% 75% 50% 25% 10% 05%
-------- ------ ------ ------ ------ ------ ------ ------
DEVILS LAKE.....
CREEL BAY 1450.5 1450.4 1450.1 1450.0 1449.8 1449.7 1449.6
STUMP LAKE.....
EAST STUMP LAKE 1450.5 1450.4 1450.1 1450.0 1449.8 1449.7 1449.6
The non-exceedance value for a listed percentage is the value
where that percentage of all model cases run were below that
lake level for the specified valid period of the outlook.
. Outlook Schedule...
- Between January and May, only the high water exceedances will be
provided with valid periods ending at the end of September.
- For June and July, both high-water and low-water exceedances
will be provided.
- For August and September, only the low-water exceedances will be
provided with valid periods ending at the end of November.
- No probability of exceedance/non-exceedance information will be
given from October through December, since lake freeze-up
levels will be given in the fall outlooks previously issued.
. Additional Information...
Wind and Wave forecasts for Devils and Stump lakes are available for
a seven day period when the lakes are sufficiently ice-free at:
www.crh.noaa.gov/fgf/hydro/lake_Fcst.php
Additionally, 7 day lake evaporation forecasts are available
during the growing season at:
www.crh.noaa.gov/fgf/climate/farm_info.php
The long-range probabilistic outlook is based on high and low lake
levels that were calculated for the valid period using multiple
scenarios of temperature and precipitation from 1949 to 2012 and
current conditions of the lake, snowcover (in winter), and soil
moisture.
A YouTube video on "How to Interpret River Outlook Products" is at:
www.youtube.com/watchv?=pSoEgvsnpv4
By providing the complete range of lake level probabilities, the
amount of risk associated with long-range planning decisions can
be determined. These probabilistic outlooks are part of Noah`s
National Weather Service`s Advanced Hydrologic Prediction
Services (AHPS).
This outlook is also presented as probability graphs of lake height
for the full period as well as weekly probabilities. The outlook
graphics and explanations that help in interpreting these
outlooks are available from the NWS Grand Forks AHPS web page
on the internet at:
water.weather.gov/ahps2/index.php?/wfo=fgf
Outlook graphics of the probabilities of exceeding various lake
levels for Devils and Stump lakes are also on out web site. They
should be available by 10:30 AM Friday. Monthly probabilistic
outlooks are usually issued on the Thursday or Friday of the week
following the first Thursday after the 15Th of the month, usually
the third or fourth week of the month.
If you have any questions, contact the NWS at 701-772-0720
You can follow us on Facebook at: www.facebook.com/NWSGrandForks
and on Twitter at: @NWSGrandForks.
$$
weather.gov/fgf
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